Reference

	The Light-Hearted Astronomer by Ken Fulton Year: 1985 Hits: 4573 Date insert: Monday, 31 December 2018
	The Monthly Sky Guide by Guy Israel, R. Brent Tully Year: 1996 Hits: 3906 Date insert: Monday, 31 December 2018
	The Night Sky Observers Guide: Volume 2, Spring & Summer by George Robert Kepple, Sanner NA, Kepple NA, Glen W. Sanner Year: 1998 Hits: 4342 Date insert: Monday, 31 December 2018
	The Official Halleys Comet Book by Brian Harpur Year: 1985 Hits: 3747 Date insert: Monday, 31 December 2018
	The Planet Observers Handbook by Fred w. Price Year: 1994 Hits: 3846 Date insert: Monday, 31 December 2018